The present invention relates to a magnetic recording and reproducing apparatus, such as a disk drive.
Magnetic recording and reproducing apparatuses are used in a wide range of fields. Particularly noteworthy in recent years has been the use of compact magnetic recording and reproducing apparatuses mounted on portable music players, compact mobile equipment, and the like.
The magnetic recording and reproducing apparatus of this kind has a box-like case. The case has a magnetic recording medium and a head disk assembly (HDA) that may include a magnetic head for recording or reproducing data to or from the magnetic recording medium built therein. The case is also mounted integrally with a circuit board that is disposed on an outside thereof and drivingly controls the HDA.
Further and further reduction in size is being lately promoted in equipment, in which the magnetic recording and reproducing apparatus of this kind is mounted, in order to enhance portability and the like. There is accordingly an increased need for further reduction in size also with the magnetic recording and reproducing apparatus.
In prior magnetic recording and reproducing apparatus, however, the circuit board is secured to the case using a plurality of screws. An attempt to form a compact magnetic recording and reproducing apparatus therefore presents the following problem.
Specifically, adopting the arrangement, in which the circuit board is screwed to the case, defies mounting of an electric signal wiring in spaces occupied by threaded holes into which screws are inserted of all spaces available on the circuit board. Moreover, of the spaces available on the circuit board, portions in contact with screw heads are glands and thus also defy mounting of the electric signal wiring.
More specifically, there is a reduction in spaces available for mounting the electric signal wiring on the circuit board by the amount equivalent to the space for threaded holes and the portion in contact with screw heads. It then becomes difficult to make the circuit board more compact. In particular, in a magnetic recording and reproducing apparatus built compactly to a size of 1 inch or smaller, the ratio of the area of openings of threaded holes occupying the circuit board becomes great. This helps make the aforementioned problem to be even more conspicuous.
To solve this problem, a proposed magnetic recording and reproducing apparatus includes a lock tab disposed on a peripheral edge of the circuit board. The lock tab extends toward a side face of the case. The lock tab is hooked onto a thick wall portion provided in a protruding condition on the side face of the case. The magnetic recording and reproducing apparatus thereby allows the circuit board to be secured to the case without using any screw. See, for example, Patent Document 1 (Japanese Patent Laid-open No. Hei 8-7556 (paragraphs 0040 through 0043, FIG. 4).